@property --rotate {
    syntax: "<angle>";
    initial-value: 132deg;
    inherits: false;
}

:root {
    --card-height: 65vh;
    --card-width: calc(var(--card-height) / 1.5);
}

.border {
    width: var(--card-width);
    height: var(--card-height);
    padding: 3px;
    position: relative;
    border-radius: 6px;
    justify-content: center;
    align-items: center;
    text-align: center;
    display: flex;
    font-size: 1.5em;
    color: rgb(88 199 250 / 0%);
    cursor: pointer;
}

/* .border::before {
    content: "";
    width: 100%;
    height: 98%;
    border-radius: 8px;
    background-image: linear-gradient(var(--rotate), #ebdd29, #f2ff00 43%, #4e00c2);
    position: absolute;
    z-index: -1;
    top: 1%;
    left: 0%;
    animation: spin 2.5s linear infinite;
} */

/* 橙色 */
.orange::before {
    content: "";
    width: 100%;
    height: 98%;
    border-radius: 8px;
    background-image: linear-gradient(var(--rotate), #8b820a, #e6ed63 43%, #5e6423);
    position: absolute;
    z-index: -1;
    top: 1%;
    left: 0%;
    animation: spin 2.5s linear infinite;
}

/* 紫色 */
.purple::before {
    content: "";
    width: 100%;
    height: 98%;
    border-radius: 8px;
    background-image: linear-gradient(var(--rotate), #561383, #aa07ea 43%, #5c4366);
    position: absolute;
    z-index: -1;
    top: 1%;
    left: 0%;
    animation: spin 2.5s linear infinite;
}

/* 蓝色 */
.blue::before {
    content: "";
    width: 100%;
    height: 98%;
    border-radius: 8px;
    background-image: linear-gradient(var(--rotate), #5552f3, #0a0461 43%, #504a9f);
    position: absolute;
    z-index: -1;
    top: 1%;
    left: 0%;
    animation: spin 2.5s linear infinite;
}

/* 绿色 */
.green::before {
    content: "";
    width: 100%;
    height: 98%;
    border-radius: 8px;
    background-image: linear-gradient(var(--rotate), rgb(35 146 41), rgb(67 206 67 / 64%) 43%, rgb(17 113 49));
    position: absolute;
    z-index: -1;
    top: 1%;
    left: 0%;
    animation: spin 2.5s linear infinite;
}

/* 灰色 */
.grey::before {
    content: "";
    width: 100%;
    height: 98%;
    border-radius: 8px;
    background-image: linear-gradient(var(--rotate), grey, #ccc 43%, #eee);
    position: absolute;
    z-index: -1;
    top: 1%;
    left: 0%;
    animation: spin 2.5s linear infinite;
}

@keyframes spin {
    0% {
        --rotate: 0deg;
    }

    100% {
        --rotate: 360deg;
    }
}